Oil dipstick illuminators



H. C. NESBITT Filed Aug. 16, 1967 OIL DIPSTICK ILLUMINATORS June 3, 1969 United States Patent 3,448,332 OIL DIPSTICK ILLUMINATORS Harvey C. Nesbitt, 84 Fullerton Road, Calgary, Alberta, Canada Filed Aug. 16, 1967, Ser. No. 661,102 Int. Cl. B60q 9/00 US. Cl. 315-77 Claims ABSTRACT OF THE DISCLOSURE The oil dipstick illuminator includes an upright tubular fixture mounted on the oil container top adjacent the dipstick opening. The upper part of the fixture has a socket receiving a double contact electric lamp energizable by a source of current under the control of a switch arm pivoted in and swinging outwardly of the lower part of the fixture. The dipstick flange normally engages and holds the switch arm so positioned that the switch contacts are open, but when the dipstick is removed, the switch arm is permitted to swing outwardly of the fixture under spring pressure to a position wherein the switch contacts are engaged and the electric lamp is energized.

My invention relates to improvements in equipment for lighting dipsticks and more particularly to crankcase oil dipstick lights for automobiles.

The reading of the liquid level indication on a dipstick and subsequent replacement of the dipstick in the engine crankcase of an automobile under poor lighting conditions, such as at night, or in a garage, can be frustrating and time wasting, especially in the absence of suitable overhead lighting in garages, and more particularly because the usual engine covering hood of a vehicle tends to cast a shadow onto the engine crankcase even in broad daylight.

An important object of my invention is to provide means for electrically lighting a zone in the vicinity of the oil dipstick of a vehicle engine and which lighting means is automatically energized upon removal of the dipstick from the engine crankcase.

Another object of the invention is the provision of engine oil dipstick lighting equipment which can be manufactured and installed inexpensively at the vehicle factory, or sold by retailers and readily installed by a car owner.

A still further object of my invention is the provision of engine oil dipstick lighting equipment with an adjustable switch facilitating the attachment of the equipment to various kinds and sizes of engines.

Other objects and advantages of my invention will become apparent during the course of the following description, taken in connection with the accompanying drawing, forming a part of this specification, and in which drawing,

FIG. 1 is a fragmentary view in central vertical section of my engine oil dipstick illuminator and support bracket attached to an engine crankcase provided with a dipstick tube, the dipstick being disposed in the tube.

FIG. 2 is a fragmentary view partly in side elevation and partly in central vertical section of my engine oil dipstick illuminator and support bracket, the dipstick having been removed from the dipstick tube.

FIG. 3 is a top plan view of the support bracket.

FIG. 4 is a diagrammatic view showing the electric Wiring circuit for the dipstick illuminating equipment.

In the drawing which, for the purpose of illustration, shows a preferred form of the invention, and wherein similar reference characters denote corersponding parts throughout the several views, the letter A generally designates the dipstick lighting equipment for lighting a dip See stick 5 of the type removably insertable downwardly into a liquid container such as an engine crankcase '6 having a dipstick opening 7 in its top and receiving the dipstick 5 through a guide tube 8 fitting the opening. Clamped to the dipstick tube 8, as by a bracket 9, a set screw 10, engaging the tube 8, and a screw 11, is a tubular metal fixture 12 including an upper portion 13 and a lower portion 14. Mounted in the upper portion 13 is a cylindrical electric light socket 15 having an insulative base 16 provided with two spaced terminals 17, 18 in engagement with double contacts 19, 20 respectively in the base 21 of an electric lamp 22 that is inserted in the socket 15. The electric lamp 22, when energized, illuminates a zone in the vicinity of the dipstick 5 and the dipstick tube 8 via a light aperture 23 in the upper portion 13 of the fixture 12 facing the dipstick 5.

Diametrically disposed in the lower portion 14 of said fixture 12 is the central stem 24 of a rigid circular contact disc 25 which is adjustable in the direction of the length of the stem 24, as by rotation of a screw threaded portion 26 of the stem 24 in the cylindrical wall of the lower portion 14 of the fixture 12.

In the example shown, the outer threaded portion 26 -of the stem 24 is provided with a slotted head 27 to facilitate adjustment of the contact disc 25 by means of a screw driver, and the set position of the contact disc 25 is remova'bly secured by a locknut 28. Pivotally mounted in the lower portion 14 of the tubular fixture 12, as by a pin 29 extending crosswise through the fixture 12 is the apex of a sector-shaped switch arm 30 having pressed into a notch 31 in its arcuate margin 32 an insulative strip 33 to which a movable contact 34 is affixed as by a rivet 35. The switch arm 30 is movable between a first position as shown in FIGS. 2 and 4 and a second position as shown in FIG. 1 to shift said movable contact 34 respectively into and out of engagement and electrical connection with the rigid contact 25.

Extending between and electrically connecting the movable contact 34 and one terminal 18 of the lamp socket 15 is a flexible conductor wire 36 which may be provided intermediate its ends with a short length of insulative covering 37 to prevent grounding or short circuiting of the flexible wire 36 against any other metallic parts within the fixture 12. The switch arm 30 is movable through a slot-shaped passageway 38 and has a lower downwardly and outwardly extending free end portion 39 which may swing outwardly into the path of travel of an annular flange portion 40 of the dipstick 5 during removal thereof from the dipstick tube 8.

Any suitable means may be provided for biasing the switch arm 30 for outward swinging movement, and in the example shown, I provide an expansion coil spring 41 that is held compressed between the switch arm 30 and the lower portion 14 of the tubular fixture 12 as by pins 42, 43, one 42 projecting from the switch arm 30 and the other 43 projecting from a screw 44 threaded into the fixture 12.

Upon insertion of the dipstick 5 into the crankcase 6 through the dipstick opening 8, the switch arm 30 is engaged and swung inwardly by the annular flange 40 of the dipstick 5 and this inward swinging of the switch arm 30 compresses the coil spring 41, moves the movable contact 34 away from the rigid contact 25 thus deenergizing the electric lamp 22.

In the operation of the equipment A, the switch contacts 25, 34 are normally held open as long as the switch arm 30 is held in its inward position by the annular flange 40 of the dipstick 5 in the dipstick tube 8. Upon removal of the dipstick 5, the switch arm 30 is free to swing outwardly in response to the urging of the expansion coil spring 41 and when this occurs the movable contact 34 engages the rigid contact 25 thus connecting the source of current 45 via conductor 46 to the electric lamp 22 by way of the circuit shown in FIG. 4. In the example shown, more particularly in FIG. 3, I provide the bracket 9 with a slot 47 through which the screw 11 extends in order to fasten the fixture to the bracket in any one of a number of set positions of adjustment of the spacing of the fixture 12 relative to the dipstick tube 8.

Various changes may be made in the form of invention herein shown and described without departing from the spirit of the invention and the scope of the following claims.

I claim:

1. Equipment for lighting a dipstick of the type removably insertible into a liquid container having a dipstick opening in its top, said equipment comprising a fixture secured to said container top adjacent said dipstick opening, an electric circuit including a source of current, an electric lamp mounted on the fixture, a switch having a rigid contact mounted within the fixture, a switch arm movably mounted on said fixture, an insulated movable contact secured to the movable switch arm, and a flexible conductor extending between the movable contact and the lamp, said switch arm being movable between first and second positions to respectively shift said movable contact into and out of electrical engagement with said rigid contact, a spring secured to the fixture and urging said switch arm into said first position wherein said movable contact engages said rigid contact, said switch arm being engaged and shifted into said second position by said dipstick upon insertion thereof into said dipstick opening thereby disconnecting said source of current from said lamp.

2. Equipment as defined in claim 1, said fixture being tubular and having an aperture for light from said lamp and a passageway for movement of said switch arm therethrough, said light aperture and said switch arm passageway facing said dipstick in said dipstick opening.

3. Equipment as defined in claim 1, said rigid contact including means for adjusting its position toward and away from said movable contact.

4. Equipment as defined in claim 1, said fixture including a lamp socket having an insulative base pro- 'vided with two spaced terminals, and said electric lamp having double contacts in its base respectively engaging said two spaced terminals.

5. Equipment as ldefined in claim 2, said tubular fixture having an upper portion in which said lamp is mounted, and a lower portion containing said switch and said switch arm.

No references cited.

JAMES W. LAWRENCE, Primary Examiner.

C. R. CAMPBELL, Assistant Examiner.

US. Cl. X.R. 

